Mainship 34 Motor Cruiser
By Jack Hornor
Revised by BoatUS editors in October 2012
The Mainship 34 was intended as a fuel-efficient family cruiser and its introduction just before the fuel crisis in the late 1970s practically ensured its instant success. Since that time, this Mainship model has become one of the most popular 34-foot cruisers ever built. The older models remain reasonably priced and one of the better used boat values for boaters content with cruising along at a leisurely pace and willing to deal with the maintenance of an older boat. The Mainship 34 Motor Cruiser is often referred to as the "Mainship Trawler", and although the design somewhat resembles this genre, this is not a trawler. The single engine, semi-displacement hull form with deep forefoot and a long deep keel actually more closely resembles Down East-style workboats and cruisers.
Two years after the introduction of the Mainship 34 Motor Cruiser a modified Mainship II was added to the series and, in 1983, the Mainship III replaced both prior models. The Mainship III remained in production until 1988. (Note: The later production Mainship 34 Sedan and Pilot models are not based on the original 34 Motor Cruiser design.)
The Mainship 34's hull is constructed of solid fiberglass laminate and the decks are sandwich construction with fiberglass outer layers and a balsa wood core. For the most, part hull construction is sound and these older boat show few signs of deterioration. Some osmotic blistering and elevated moisture below the waterline is common and can most often be treated with local repair of effected areas.
Two other potentially serious problems seen in older models are fuel tank leaks and deck deterioration and these areas should be very thoroughly inspected when considering buying this model.
The most notable differences between the original Mainship and the Mainship II and III models are the size of the cockpit and shape of the sheer. Goldilocks must have had some influence on Mainship's cockpit design because it seems the first was too small, the second too large and the third just right. The original Mainship 34 model had a short (barely six feet in depth) cockpit with a cabin top that extended several feet aft over the cockpit and made it appear even smaller than it was. The Mainship II eliminated the extended cabin top and the cockpit length increased by nearly three feet. The sheer was stepped down six inches at the aft end of the cabin trunk resulting in a more open cockpit and an appearance that more closely resembled a sedan cruiser.
The loss of nearly 30 square feet of cabin space did not prove popular and in 1983 the new Mainship III added more than a foot back to the main saloon with a resulting reduction in cockpit space.
Several other exterior features of the Mainship 34 series are bound to appeal to potential owners. The side decks are wide enough for safe passage and well guarded with handholds and rails well above normal knee height. The foredeck is small but secure for handling ground tackle and there is no exterior teak to maintain. There were almost no changes to the interior arrangement between the Mainship I, II and III models. All featured an owner's V-berth cabin forward, followed by a U-shaped galley to port and a head to starboard. Up two steps is the main saloon with starboard helm and furniture arranged to the owner's preference. This single stateroom plan is well suited to a cruising couple. However, the only accommodation for guests is a convertible couch in the main saloon that offers little privacy.
The owner&s stateroom forward has a comfortable double berth with plenty of storage below, but there are only two small hanging lockers, each hardly large enough for more than a jacket and a few pairs of slacks. The head has full standing headroom and a very nice stall shower adjacent to the head, but a measly 40 to 50 gallon water supply (depending on year and model) will have you taking navy showers to conserve water. In my opinion, a boat this size should have at least a 100-gallon water supply.
The main saloon is comfortable with nearly 360 degrees of visibility and 6' 3" of headroom throughout. There is a helm to starboard which has poor visibility over the bow at operating speed and is seldom used by most owners.
The original Mainship 34 was powered by a single 160 hp Perkins diesel engine. In 1980, a 200 hp Perkins diesel was added as an option and, in the last two years of production, Mainship III models were powered by 220 hp Johnson and Tower marine diesels.
Equipped with the standard 160 hp Perkins the Mainship will cruise at 10 to 11 knots when pushed to the top end of her continuous RPM operating range. At these speeds she will burn something in the neighborhood of 6 gallons of fuel per hour resulting in an effective cruising range of 350 to 400 miles. At a slower pace of 7 knots, fuel consumption drops to a range of 2 gallons per hour and the cruising range nearly doubles.
The optional 200 hp Perkins and later 220 hp Johnson & Tower engines will add 10% or a little better to the 34's performance and, for those who prefer to do their cruising at a little faster pace, the more powerful engines are a good choice. In rough conditions the Mainship 34 can be a bit of a wet boat but she doesn't pound, tracks a true course and is responsive to her helm.
There were over 900 Mainship 34 hulls built over the 10-year production period, many of which were originally sold through dealers along the East Coast and in the Great Lakes.
Classically styled boats have enjoyed a tremendous resurgence over the last few years as evidenced by the proliferation of "picnic" and "commuter" models on display at recent boat shows at prices that would likely make J. P. Morgan wince. The Mainship 34 is no Hinckley Picnic Express, but its combination of styling, comfortable accommodations, economical performance and reasonable price keeps it in demand and a good choice for economy-minded boaters everywhere.
Naval architect Jack Hornor was the principal surveyor and designer for Marine Survey & Design, Co., based in Annapolis, MD. He was on the boards of the American Boat and Yacht Council, the National Association of Marine Surveyors, and the Society of Boat and Yacht Designers. He and his wife sailed their Catalina 42, Legacy, based on Maryland's Eastern Shore.